Adjustable clamp and bolt



Dec. 6, 1955 GAMURA 2,725,793

ADJUSTABLE CLAMP AND BOLT Filed March 18, 1953 I M/Zfifl/ A. Gamura 2 United States Patent 2,725,793 ADJUSTABLE CLAMP AND Borr Michael A. Gamura, Detroit, Mich. Application March 18, 1953, Serial No. 343,157 3 Claims. (Cl. 90-59) This invention relates to improvements in machine tools and more particularly to an adjustable clamp for securing a work piece on the bed of any conventional power tool.

The primary object of this invention resides in the provision of a device which is capable of securing a work piece to -a machine adapted for. milling, boring, planing, shaping and the like in a secure manner without requiring a large assortment of bolts and blocks of various sizes.

Still further objects of the invention reside in the provision of an adjustable clamp and bolt therefor which is provided with means to compensate for work pieces of varying heights thus enabling a machinist to save a considerable amount of time and effort in setting up his machine.

Still further objects of the invention reside in the provision of an adjustable clamp and bolt that is strong and durable, simple in construction and manufacture, capable of being supplied in varying sets of which each subsequent set has a considerable increased range of utility.

These, together with the various ancillary objects and features of the invention which will become apparent as the following description proceeds, are attained by this adjustable clamp and bolt therefor, a preferred embodiment of which has been illustrated in the accompanying drawings, by way of example only, wherein:

Figure 1 is a side elevational view showing the adjustable clamp and bolt as operatively employed in se curing a work piece to the bed of a machine tool;

Figure 2 is a vertical sectional view as taken along the plane of line 2-2 in Figure 1 showing the construction of the step block and the leg of the clamp to which it is attached;

Figure 3 is a vertical sectional view as taken along the plane of line 33 in Figure 1 illustrating the construction of the clamp and of the bolt used to hold the clamp in place in engagement with a work piece; and

Figure 4 is a horizontal sectional view as taken along the plane of line 4-4 in Figure 1 showing the construction of the stop plate for limiting the position of the step block relative to the leg of the clamp.

With continuing reference to the accompanying drawings wherein like reference numerals designate similar parts throughout the various views, reference numeral generally indicates a work piece which it is desired to hold in place by means of the clamp bar 12 having a Work piece engaging portion 14 extending downwardly therefrom and adapted to hold the Work piece 10 on the bed of a machine. The clamp bar 12 is provided with an elongated slot or aperture 16 therethrough medially the ends of the bar 12 and has a down wardly extending leg 18 provided with serrations forming teeth 20 on either side at the outer end thereof. The leg 18 has a stop plate 22 preferably integral with the inner vertical edge of the leg 18. A further stop plate 24 is integrally formed with the lower edge of the leg 18.

A step block 26 having arms 28 and 30 provided with teeth 32 and 34 on the inner surfaces thereof is slidablyengaged with the teeth 20 on the leg 18. The innermost position of the step block 26 is limited by the plate 22 and the lowermost position is limited by the stop plate 24. The space between the teeth 20 and the stop plate 22 is provided to permit the step block 26 to be adjusted without removing the step block from engagement with the leg 18. The step block is provided with a semi-cylindrical lower portion 36 to compensate for the small differences in height possible between the Work piece 10 and the increment in height between the teeth 20.

Extending through the aperture 16 is a threaded bolt 38 having a threaded upper end and provided with a substantially u-shaped member 40 at the lower portions thereof. The U-shaped member 40 includes a pair of arms 42 and 44' which have their inner surfaces serrated to form teeth 46 and 48 whichengage the teeth 52 on either side of aT-bolt 50 having its lower plate 54 which is adapted to be slidably inserted within the T- shaped slot 56 in the bed of themachine on which the clamp is to be used. The threaded end of the bolt 33 extends upwardly beyond the top of the clamp bar 12 and is held in position by means of nut 58. It is to be noted that the T-bolt 50 includes a stop plate 60 integrally formed with the upper end thereof which together with the side stop plates 62 and 64 provide stop means for the member 40.

To secure the work piece 10 on the bed of the machine, it is merely necessary to slide the T-bolt 50 into a selected slot 56 in the bed of the machine. Then, the work piece engaging portion 14 can be positioned over the work piece 10 and'then, the U-shaped member 49 can be positioned relative to the T-bolt 50 and the step block 26 can be adjusted and positioned relative to the leg 18. Upon tightening of the nut 58, the clamp bar 12 will be drawn downwardly to hold the work piece engaging portion 14 in engagement with the work piece 10.

Since from the foregoing, the construction and advantages of this adjustable clamp and bolt are readily apparent, further description is believed to be unnecessary.

However, since numerous modifications will readily occur to those skilled in the art after a consideration of the foregoing specification and accompanying drawings, it is not intended to limit the invention to the precise embodiment shown and described, but all suitable modifications and equivalents may be readily resorted to which fall within the scope of the appended claims.

What is claimed as new is as follows:

1. A work piece securing clamp comprising a horizontal clamp bar having a work piece engaging portion at one end thereof and a serrated leg integral with said clamp bar at the other end thereof, a serrated step block engaging said leg, a serrated T-bolt for engagement within a T-slot in a machine tool table, a serrated bolt adjustably engaging said T-bolt, said serrated bolt having a threaded upper end, said clamp bar having an aperture therethrough medial the ends thereof, said threaded upper end extending through said aperture, and a nut secured about said threaded upper end engaging said clamp bar, said step block being substantially U- shaped in configuration having a pair of upwardly extending arms interconnected by a semi-cylindrical lower end to compensate for difierences in height of a work piece, the serrations on said step block forming vertically spaced teeth on the inner surfaces of said arms, said arms being slidably threadedly embracingly engaged about said leg, said leg having an integrally formed vertically extending stop plate for limiting the horizontal position of said arms relative to said leg, said leg having a horizontally extending stop plate integrally formed with said leg and engageable with the lowermost of the serrations on said step block to limit the vertical position of said arms relative to said leg, including a substantially U-shaped member having teeth formed on the inner surfaces thereof, said U-shaped member embracing said T-bolt.

2. An adjustable clamp comprising a bar having a work engaging portion at one extremity, a downwardly projecting leg integral with the other extremity, and being vertically apertured intermediately of its length, said leg having a plurality of horizontal teeth arranged one beneath another and extending across opposite sides thereof for a portion of their width, a U-shaped step block materially narrower than said leg adapted to rest upon a work table with its spaced extremities extending upwardly, a plurality of horizontal teeth arranged one above the other on the opposed inner faces of said spaced extremities to engage the teeth on the leg, means on the leg for preventing complete lateral disengagement of the block therefrom, the relative widths of the leg and step block being such that the block is adapted to be moved laterally'a sufficient distance to release its teeth from the teeth on the leg, thereby permitting vertical adjustment of the step block relative to the leg, means for limiting the vertical adjustment of the step block relative to the leg, a bolt extending vertically through the aperture and threaded from its upper extremity, a nut on said threaded extremity, and

said serrated bolt means on the lower extremity of the bolt adapted to engage the work table.

3. An adjustable clamp comprising a bar having a work engaging portion at one extremity, a downwardly projecting leg at its opposite extremity, and being vertically apertured intermediately of its length, a bolt threaded from its upper extremity extending downwardly through said aperture, a nut on the upper extremity of the bolt, the lower extremity of the bolt terminating in an inverted U-shaped portion, horizontal teeth formed one above another across the opposed inner faces of said U-shaped portion, a member provided at its lower extremity with means for attachment to a work table, said member being materially wider than said U-shaped portion and having horizontal teeth formed one above the other on opposite sides thereof to coact with the teeth on said U-shaped portion, the teeth on said member extending only part way across its width whereby said member is adapted to be moved laterally relative to said bolt to disengage its teeth from the teeth on the U-shaped portion of the bolt, means for preventing complete disengagement of the member from said U-shaped portion, and means extending downwardly from the leg adapted to bear upon the work table.

References Cited in the file of this patent UNITED STATES PATENTS 954,481 Trautner Apr. 12, 1910 1,072,363 Roberts Sept. 2, 1913 1,420,147 Roberts June 20, 1922 

